The Internet comprises a vast number of computers interconnected so that information can be exchanged among the computers. Various protocol and other interface standards have been developed for the Internet so that each computer will understand information of the other computers. The World-Wide Web ("WWW") is a subset of the Internet computers that support the Hypertext Transfer Protocol ("HTTP"). HTTP is an application-level protocol for distributed, collaborative, hypertext information systems that defines the format and contents of messages and responses sent between client programs ("clients") and server programs ("servers") over the Internet. In addition, HTTP is a generic, stateless, object-oriented protocol which can be used for many other tasks, such as name servers and distributed object management systems, through various extensions.
The Internet facilitates information exchange between servers and clients that are located throughout the world. Each computer on the Internet has a unique address (e.g., "acme.com"). When a client wishes to access a resource (e.g., document), the client specifies a Uniform Resource Locator ("URL") that uniquely identifies the computer on which the server executes and the resource. An example of a URL is "http://acme.com/page1." In this example, the server is identified by "acme.com" and the resource is identified by "page1." The URL has two parts: a scheme and a scheme-specific part. The scheme identifies the high-level protocol through which the information is to be exchanged, and the scheme-specific part contains additional information that identifies the server computer and the resource. The "http" at the beginning of the example URL identifies the scheme and indicates that the remainder of the URL should be interpreted according to HTTP. The remainder specifies a server computer (e.g., "acme.com") followed by additional information that is specific to the server. For example, the additional information may be a path name within the server computer to a Hypertext Markup Language ("HTML") document.
HTML is a page description language that is used to specify the format and layout of Web pages. When a Web browser receives a URL that identifies a Web page, it retrieves via the WWW an HTML document that describes that Web page. The browser then processes that HTML document and displays the Web page that is described by the document. HTML and various extensions to HTML provide a rich set of tags that define the formatting and content of the page to be displayed. The tags can be as simple as indicating that text is to be displayed in italics or as complex as indicating that a computer program is to be executed to provide the content of a portion of the Web page. The Web pages are usually defined to include graphical components. For example, an HTML document may contain a URL that identifies a bitmap that is to be displayed as part of the Web page. When a Web browser encounters such a URL within an HTML document, the browser uses the URL to locate and retrieve the bitmap and then display the bitmap as part of the Web page.
Microsoft Corporation has defined various extension to HTML. One such extension is known as a &lt;marquee&gt; tag. The &lt;marquee&gt; tag indicates that certain text is to be scrolled within a marquee window on a Web page. The attributes of the &lt;marquee&gt; tag specify the size of the marquee window and the direction and speed of scrolling. The &lt;marquee&gt; tag thus provides a visual effect that is similar to the electronic marquees found on some buildings that display the headline news.
Another extension to HTML is known as an &lt;object&gt; tag. An &lt;object&gt; tag specifies computer code that is to be executed to generate content for the Web page. The &lt;object&gt; tag includes parameters that are to be provided to the computer code to control its execution. The computer code is an ActiveX object (i.e., ActiveX control) that supports an interface standard that is described in Understanding ActiveX and OLE, by David Chappell and published by Microsoft Press in 1996, which is hereby incorporated by reference. The &lt;object&gt; tag includes information that identifies the object and the size of the object window in which the object can display the content that it generates. The ActiveX standard defines a mechanism through which an object can notify the browser of certain events. For example, if a user clicks on the object window, the object could notify the browser that a click was received. The browser could then take some action. The HTML document may even include instructions in a scripting language, such as Visual Basic (VB) Scripting, that are to be executed when an object generates an event. When the browser is notified of an event, it then executes the script for that event. The ActiveX standard also defines a mechanism by which the browser can set attributes of the object. The object exposes its functionality via OLE automation.
The &lt;marquee&gt; tag provides a useful, but limited mechanism, for scrolling text on a Web page. It would be desirable to have a mechanism that provides sophisticated animation of arbitrary information on a Web page.